Release channel re-activated

The Ashokan Release Channel has been re-activated after a shutdown during Winter Storm Finn. Now that Mt. Marion stream gauge has dropped below the action stage of 18 ft,  NYCDEP will resume releases, increasing from 0 MGD to 600 MGD (928 cfs) in a series of steps that started today, January 11, at approximately 8 AM and will continue throughout the day concluding on or about 7:00 PM.

The releases are operating according to the Interim Release Protocol (IRP) to draw reservoir storage toward the seasonal storage objective of 90%. Ashokan Reservoir storage is 96.4 % today. Turbidity of the water in the release channel is 16.0 NTU. The Catskill Aqueduct is online at a flow rate of 550 MGD.

NYCDEP will continue to monitor conditions and make additional adjustments pursuant to the IRP, which stipulates shut down of release channel when creek level is within 1 foot of the “Action Stage” (18′) and is forecasted to reach “Action Stage”, as predicted on the National Weather Service forecast for Mt Marion stream gauge.

Flooding at Saugerties, January 10, 2024

Storm tide from Winter Storm Finn covered Lighthouse Drive at noon on January 10, 2024.

Winter Storm Finn delivered tidal flooding to the Saugerties waterfront midday on Wednesday, January 10, 2024, and Winter Storm Gerri is forecasted to deliver similar flooding on Saturday. On Wednesday morning, the Battery tide gauge in Manhattan registered a surge over 4 feet at low tide and nearly 3 feet at high tide. This surge continued up the Hudson River, and runoff from over 2″ of rainfall on snow overnight added to the tidal surge. According to the Turkey Point tide gauge, the water level crested above 8 feet, which was over 3.5 feet above normal high tide and slightly higher than flood levels on December 18, 2023. At high tide today at 12:15PM in Saugerties, the pavement of Lighthouse Drive was covered in water.

Turkey Point tide gauge showed the water level crested at 8.09 feet at high tide, nearly 3.7 feet above normal.

Tracking Winter Storm Gerri, the Stevens Flood Advisory System at Davidson Laboratory is forecasting 3 to 4 feet of surge on Saturday afternoon at high tide, bringing the water back up to similar levels as Finn. High tide is at 3PM on Saturday, January 13 at Saugerties.

The level of water in the tidal portion of Esopus Creek is minimally affected by the shape or depth of the channel bottom at high tide. No matter how deep the channel is, the tide reaches an elevation established by the water surface elevation in the Hudson River as indicated by the Turkey Point tide station

Screenshot of Stevens flood forecast for Tivoli/Saugerties showing surge predictions for Winter Storms Finn and Gerri. For the latest forecast, visit the Stevens Flood Advisory website.

Release channel ready for shut down in response to rainfall

NYCDEP said it is prepared to shut down the release channel when the Lower Esopus water level rises. The Interim Release Protocol (IRP) stipulates shut down of release channel when creek level is within 1 foot of the “Action Stage” (18′) and is forecasted to reach “Action Stage”, as predicted on the National Weather Service forecast for Mt Marion stream gauge.

The Mount Marion forecast from the National Weather Service predicts the river stage to reach action level overnight Tuesday and peak near 19.9 feet by noon on Wednesday, January 10th.

The Ashokan Release Channel is continuing to operate at its maximum rate of 600 MGD (928 cfs) today and has been operating at this rate since December 22. Ashokan Reservoir storage peaked on December 22 at 99.4% and has been on the decline since. Ashokan Reservoir storage is currently at 93.9%, and the turbidity of the water in the release channel is 15.9 NTU. The Catskill Aqueduct is online and diverting 550 MGD for water supply. The release channel is prepared to shut down when water level reached 17 ft at Mt Marion stream gauge.

For the latest information see the Mt Marion stream gauge.

Ashokan Release Channel reactivated

The Ashokan Release Channel has been reactivated to draw Ashokan Reservoir storage toward the Conditional Seasonal Storage Objective (CSSO) now that the Mt. Marion gauge has dropped below the action stage of 18 ft.  After the shutdown during the storm event, NYCDEP will increase the Ashokan Release Channel from 0 MGD to 120 MGD (186 cfs) starting today in a series of steps.

Ashokan Reservoir storage is 97.3% today, the CSSO is 90.0%.  Turbidity of the water in the release channel is 1.7 NTU.

The Natiional Weather Service forecast for the Mount Marion gauge predicts that the stream level will continue to decrease over the next 72 hours.

Additional adjustments may be made to releases in repsonse to reservoir and weahter conditions pursuant to the Interim Release Protocol.

Coastal Storm, 12/18/23

On December 18, 2023, the water level at Saugerties (Turkey Point, Hudson River tide gauge station) peaked at 5:24 PM at 8.0′ above MLLW. This was 4′ above the normal high tide. The high water was driven by a combination of tidal surge and run-off from rainfall totals of 3.5 to 4.5 inches. By comparison, winter storm Elliot (bomb cyclone) on December 23rd, 2022, reached a slightly higher level of 8.3′ above MLLW, was primarily surge from the ocean, and unaccompanied by much precipitation. Note that the level of water in the tidal Esopus Creek when the tide is high is minimally affected by the shape or depth of the channel bottom. No matter how deep the channel is, the tide reaches an elevation established by the water surface elevation in the Hudson River.

Ashokan Releases shut down, 12/18

NYC DEP shut down the Ashokan Release Channel just after 6:00 AM this morning, December 18th. This is due to the Mt Marion USGS gage reaching 17 ft (1 ft below action stage). The flow was reduced from 309 cfs to zero. The release channel will stay closed until the Mt Marion water level falls below action stage and reservoir conditions are assessed. Ashokan Reservoir storage is currently at 90.5% with a 10.9 BG void.

Storm tide forecasted for Monday, 12/18

For Monday, December 18th, the Stevens Flood Advisory System is forecasting a storm surge of 3 to 4 feet atop the evening’s high tide, which may cause moderate flooding along low-lying waterfront properties. High tide along the tidal Esopus Creek in Saugerties will be 6:15 PM. The water level may reach or exceed the Moderate Flood Level of 7.2′ above Mean Low Low Water (MLLW). By comparison, last year’s winter storm Elliot on December 23rd, was at Major Flood Level and reached 8.3′ above MLLW. Although lower than last year’s storm tide, it will likely enter yards on Lighthouse Drive and Ferry Street in Saugerties.

Tivoli Bays South (and Saugerties)

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